ConnectException after reopening Connection

Question

Hi,
I tried to get advise on this from ALT, but maby better luck here.
I have my own database connection pool manager. It works just fine under normal conditions. But when there are
idle perioids for the system, the pooled Connectins become
idle too and Connections start to drop down.
I can detect that in my code, but when I try to create new Connection to the database bad things start to happen.
Connection con = DriverManager.getConnection(URL, user, password);it throws:
UNABLE TO CREATE CONNECTION: java.sql.SQLException:
Unable to connect to any hosts due to exception:
java.net.ConnectException: Connection timed out: connectThen I manually tried to select stuff from the tables, MySQL prompted:
ERROR 2013: Lost connection to MySQL server during query...ERROR 2006:
MySQL server has gone awayNo connection. Trying to reconnect...Connection id:    267
Current database: logWhy I can`t create any new Connection and why the MySQL reports those errors? Is there something going on with the DriverManager !?
Your advice appreciated!

Answer 1

I have written database connection pool and may be able to help you.
Because db connection pool manager runs in different threads, the code usually contains functionality to maintain the connection objects.
From what you described, this is what I suspect is happening
You database server somehow dies sometime during your idle time,
leaving the connections in the pool in limbo. i.e. the connection still exist in the pool object, but they have lost their respective handles to the database when the server died.
My suggestion:
1) Try to investigate wht causes the database server to die
2) Review you pool code to make sure new connections are created when
the pool is empty and a new connection is requested
3) Make sure your client code releases connections to the DB pool
when no longer needed. Do not close the connection
in your client code
=============================================
Hi,
I tried to get advise on this from ALT, but maby
better luck here.
I have my own database connection pool manager. It
works just fine under normal conditions. But when
there are
idle perioids for the system, the pooled Connectins
become
idle too and Connections start to drop down.
I can detect that in my code, but when I try to create
new Connection to the database bad things start to
happen.
Connection con = DriverManager.getConnection(URL,
user, password);it throws:
UNABLE TO CREATE CONNECTION: java.sql.SQLException:
Unable to connect to any hosts due to exception:
java.net.ConnectException: Connection timed out:
connectThen I manually tried to select stuff from the tables,
MySQL prompted:
ERROR 2013: Lost connection to MySQL server during
query...ERROR 2006:
MySQL server has gone awayNo connection. Trying to
reconnect...Connection id:    267
Current database: logWhy I can`t create any new Connection and why the
MySQL reports those errors? Is there something going
on with the DriverManager !?
Your advice appreciated!